ORIGINALPAPERApplicationofreversemicelleextractionprocessforamylaserecoveryusingresponsesurfacemethodologyManavB.BeraÆParmjitS.PanesarÆReebaPanesarÆBahadurSinghReceived:16July2007/Accepted:22October2007/Publishedonline:7November2007�Springer-Verlag2007AbstractTheeffectofdifferentprocessvariablesofreversemicelleextractionprocesslikepH,additionofsurfactant(AOT)concentrationandpotassiumchloride(KCl)concentrationonamylaserecoveryhasbeenstudiedandanalysed.Solid-statefermentationwasusedfortheproductionofamylaseenzyme.Responsesurfacemeth-odology(RSM)usingcentralcompositerotatabledesign(CCRD)wasemployedtoanalyseandoptimizetheenzymeextractionprocess.Theregressionanalysisindi-catesthattheeffectofAOTconcentration,andKClconcentrationweresignificant,whereastheeffectofpHwasnon-significantonenzymerecovery.Forthemaximumrecoveryofenzyme,theoptimumoperatingconditionforpH,AOTconcentration(M)andKClconcentrationwere10.43,0.05and1.00,respectively.Undertheseoptimalconditions,theenzymerecoverywas83.16%.KeywordsAmylase�Reversemicelleextraction�Optimization�ResponsesurfacemethodologyIntroductionEnzymesmakeidealcatalystsinfoodindustriesowingtotheirspecificity,mildreactionconditionandnon-toxicity.Micro-organismsarethemostconvenientsourceforenzymeproduction.Thereareseveralmicro-organisms,whichserveassourcesforenzymeproductionandapprovedbytheFDAforfooduse.Generally,intheindustry,crudeenzymesareproducedafterthecentrifugationofthefermentationbroth.Theenzymaticactivityofthesecrudeenzymesisverylowandsoitisrequiredinlargequantitiesforfoodprocessing.Thecrudeenzymesusuallyhaveoff-flavour,requiremorespaceduringstorageandtransportation.Therefore,down-streamprocessingofthesecrudeenzymesisrequiredtoextracttheenzymefromthebroth,purifyanddrythem,sothatitcanbeconvenientlystoredandusedinsmallquantities[1].Commercialinterestincost-effectivemeth-odsthatcanseparate,concentrateandpurifyproteinscontinuouslyandbeeasilyscaled-up,hasincreasedmarkedlyinrecentyears.Inthiscontext,liquid–liquidextractionusingreversemicellarorganicsolventshasbeenfoundtohavethispotential[2].IthasbeenextensivelystudiedwithmodelproteinssuchascytochromeC,ribo-nuclease,myoglobin,bovineserumalbumin,etc.However,notmuchworkhasbeendoneontheactualsystemoffermentationbroth[3–6].Optimizationofparametersbytheconventionalmethoddoesnotdepicttheinteractiveeffectofallthevariablesandinvolvechangingoneindependentvariablewhileunchangingallothersatafixedlevel,whichisextremelytime-consumingandexpensiveforalargenumberofvariables[7].Statisticalmethodologiescanbeappliedinbiotechnologicalprocessestoobservetheeffectandinteractionsofthemajorfactors.Responsesurfacemeth-odology(RSM)isacollectionofstatisticaltechniquesfordesigningexperiments,buildingmodels,evaluatingtheeffectoffactorsandsearchingforoptimumconditionsfordesirableresponses.RSMcanidentifyandquantifythevariousinteractionsamongdifferentparametersandithasbeenappliedforoptimizationofmediumandculturalM.B.Bera�P.S.Panesar(&)�R.Panesar�B.SinghBiotechnologyResearchLaboratory,DepartmentofFoodEngineeringandTechnology,SantLongowalInstituteofEngineeringandTechnology,Longowal148106,Punjab,Indiae-mail:pspanesarrr@yahoo.com123BioprocessBiosystEng(2008)31:379–384DOI10.1007/s00449-007-0172-6conditionsinbioprocesses[8,9].Keepingtheaboveinview,theRSMwasemployedinthepresentworktooptimizevariousprocessvariables,i.e.pH,...
